Solar Craft Shed setup

[DThames]

Often appliances draw less than what the doc says. You can find watt meters on Amazon for $15 and just plug the AC into it. Let it run for 24 hours and record some data.


You'll want the AC running for 24-hours and see what happens. We set our window AC in the ECO mode and it shuts down completely when the set point is hit. Our small (6,000 btu) AC didn't keep up on hot days until we put in a ceiling. Our shop is 12x16. This made a HUGE difference for the AC and how much power we needed. Did I say HUGE?!

Ideally, you are running your AC in the daytime using solar AND charging your batteries at the same time. In the overnight hours, the AC does not run continuously like it does on hot days. Power consumption off the battery bank is much less than in the daytime. Maybe with your larger AC and smaller shed your unit won't be on 24/7 but will cycle off when it is caught up.

We unrolled insulation for in between our studs, added drywall and put in a drop ceiling. Did I mention the huge difference all this makes?!

You want to know how much power you need from sundown to sun rise. This is the power you need stored in batteries. You want to know how much power the shop and AC draw when you are in there doing stuff. Eventually you'll know how much power you need to generate to both run things and store power for evenings.

Issues to contend with, like these are our issues:

• Our panels don't start generating anything meaningful until late morning.
• In the hot summer sun, our panels are less efficient
• We get lots of clouds and cloudy days in the summer (in Kentucky)
• We need more than one day of power in the batteries, even in the summertime, especially in the summertime.

You have one more issue to contend with, the MAX PV INPUT of your charge controller. You mentioned a 40amp Epever. What is the voltage limit? Is it 92-volts? You want to know how much voltage your panels are producing. In series, current stays the same while voltage is additive. For example, the Canadian Solar 445W Panel @DThames suggested has a "Max power voltage (VMP): 38.3 V." If you bought two panels, you are at 38+38 or 76-volts. Adding on the two 100-watt panels you already have might push your controller past its limit and it will shut down.

"if you bought two panels, you are at 38+38 or 76-volts. Adding on the two 100-watt panels you already have might push your controller past its limit and it will shut down."

Please explain. "past its limit"

edit....100w panels are likely 12v type and not at all suitable to use with 36v (72cell) type panels. Again asking what limit are you planning to exceed, or how would you use the two panel types on one PV circuit?

 

[dcGuide]

My apologies for confusing things and being confused. Every system has limits, and the OP has already purchased equipment. It was suggested the OP purchase four or five 36-volt panels. In addition to 100-watt panels the OP also has 2 Batteries, an Epever 40A Controller and a TopBull 3000W 12V Inverter.

Please explain. "past its limit"

edit....100w panels are likely 12v type and not at all suitable to use with 36v (72cell) type panels. Again asking what limit are you planning to exceed, or how would you use the two panel types on one PV circuit?

I assumed the OP originally intended to connect two 100-watt panels to the charge controller, the controller to the batteries and the batteries to the inverter. Both the charge controller and the inverter have limits on their inputs. Can the OP use any of this current gear? What additional components will the OP need to support several 36-volt panels?

 

[DThames]

My apologies for confusing things and being confused. Every system has limits, and the OP has already purchased equipment. It was suggested the OP purchase four or five 36-volt panels. In addition to 100-watt panels the OP also has 2 Batteries, an Epever 40A Controller and a TopBull 3000W 12V Inverter.



I assumed the OP originally intended to connect two 100-watt panels to the charge controller, the controller to the batteries and the batteries to the inverter. Both the charge controller and the inverter have limits on their inputs. Can the OP use any of this current gear? What additional components will the OP need to support several 36-volt panels?

EPEver 40A can handle up towards 100v on the input, so two large 72cell in series, 2s2p would be a solution. Sit the 100w guys aside or get another charger for them.

 

[Skegeej]

Often appliances draw less than what the doc says. You can find watt meters on Amazon for $15 and just plug the AC into it. Let it run for 24 hours and record some data.


You'll want the AC running for 24-hours and see what happens. We set our window AC in the ECO mode and it shuts down completely when the set point is hit. Our small (6,000 btu) AC didn't keep up on hot days until we put in a ceiling. Our shop is 12x16. This made a HUGE difference for the AC and how much power we needed. Did I say HUGE?!

Ideally, you are running your AC in the daytime using solar AND charging your batteries at the same time. In the overnight hours, the AC does not run continuously like it does on hot days. Power consumption off the battery bank is much less than in the daytime. Maybe with your larger AC and smaller shed your unit won't be on 24/7 but will cycle off when it is caught up.

We unrolled insulation for in between our studs, added drywall and put in a drop ceiling. Did I mention the huge difference all this makes?!

You want to know how much power you need from sundown to sun rise. This is the power you need stored in batteries. You want to know how much power the shop and AC draw when you are in there doing stuff. Eventually you'll know how much power you need to generate to both run things and store power for evenings.

Issues to contend with, like these are our issues:

• Our panels don't start generating anything meaningful until late morning.
• In the hot summer sun, our panels are less efficient
• We get lots of clouds and cloudy days in the summer (in Kentucky)
• We need more than one day of power in the batteries, even in the summertime, especially in the summertime.

You have one more issue to contend with, the MAX PV INPUT of your charge controller. You mentioned a 40amp Epever. What is the voltage limit? Is it 92-volts? You want to know how much voltage your panels are producing. In series, current stays the same while voltage is additive. For example, the Canadian Solar 445W Panel @DThames suggested has a "Max power voltage (VMP): 38.3 V." If you bought two panels, you are at 38+38 or 76-volts. Adding on the two 100-watt panels you already have might push your controller past its limit and it will shut down.

Thank you for all the information

 

[Skegeej]

"if you bought two panels, you are at 38+38 or 76-volts. Adding on the two 100-watt panels you already have might push your controller past its limit and it will shut down."

Please explain. "past its limit"

edit....100w panels are likely 12v type and not at all suitable to use with 36v (72cell) type panels. Again asking what limit are you planning to exceed, or how would you use the two panel types on one PV circuit?

With that has been said am I able to use the 36v panels with the 12v batteries that I have and 12v inverter? Or does the controller handle that?

 

[DThames]

With that has been said am I able to use the 36v panels with the 12v batteries that I have and 12v inverter? Or does the controller handle that?

12v inverter runs off a 12v battery.
You said you have an EPever 40A. You really should read the manual. You will be better off if you do. The manual tells you what type and how many of what type in the "PV Array" section of the manual. There are several model of 40amp so I will not risk quoting the wrong specification but yes you can connect large panels of voltages up towards 100v on all of the models that I am familiar with. You need to find the max PV voltage input number. I think most models are 100v, some 150v, but you need to look up what yours is and know that number.

 

[Skegeej]

12v inverter runs off a 12v battery.
You said you have an EPever 40A. You really should read the manual. You will be better off if you do. The manual tells you what type and how many of what type in the "PV Array" section of the manual. There are several model of 40amp so I will not risk quoting the wrong specification but yes you can connect large panels of voltages up towards 100v on all of the models that I am familiar with. You need to find the max PV voltage input number. I think most models are 100v, some 150v, but you need to look up what yours is and know that number.
View attachment 106950

Yes, I checked and my max is 100v. I’m also able to send back my 100w panels as well so they will not be in the picture. I also see flexible panels, are they worth buying?